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Laser-scanning topographic survey of the tunnel on Line 5 of the Riyadh metro

Fast Consortium, a temporary joint venture commissioned to build Line 5 of the Saudi capital's metro, contracted Toyser to carry out the necessary work for the geometrical definition of the 12-kilometre tunnel on Line 5 of the Riyadh metro in Saudi Arabia.
In view of the difficulty involved in the data gathering process for this huge public project, Toyser proposed the use of laser-scanning technology, which would allow plotting a 3D model of points with exceptional quality in a very short time.
The scanning was scheduled to take place over a period of eighteen days. In the end, however, and given the customer's urgency, the layout of the metro line and the placement of the stations were completed in only twelve days, including working a twelve-hour day at the weekends.
Ingenious solutions
Considering that the technical equipment used is highly sensitive, and to ensure the customer's requirements were met in terms of deadlines, Toyser ruled out several options, such as the temporary importing of the laser scanner through a specialised transport firm. The deployment of the equipment in perfect conditions was ensured by booking it a seat on a flight as just another passenger; with its own ticket, of course.
A conditioning factor, and an important one at that, has involved the high temperatures; while they remained stable within the tunnel at around 35ºC, outside they ranged from 33ºC at 8 o'clock in the morning to almost 50ºC at midday, dropping to around 42ºC at 10 o'clock at night.